Page:EB1911 - Volume 19.djvu/47

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MURCIA

three years of his scientific career he had explored large parts of England and Scotland, had obtained materials for three important memoirs, as well as for two more written in conjunction with Sedgwick, and had risen to be a prominent member of the Geological Society and one of its two secretaries. Turning his attention for a little to Continental geology, he explored with Lyell the volcanic region of Auvergne, parts of southern France, northern Italy, Tirol and Switzerland. A little later, with Sedgwick as 'his companion, he attacked the difficult problem of the geological structure of the Alps, and their joint paper giving the results of their study will always be regarded as one of the classics in the literature of Alpine geology.

It was in the year 1831 that Murchison found the field in which the chief work of his life was to be accomplished. Acting on a suggestion made to him by Buckland he betook himself to the borders of Wales, with the view of endeavouring to discover whether the greywacke rocks underlying the Old Red Sandstone could be grouped into a definite order of succession, as the Secondary rocks of England had been made to tell their story by William Smith. For several years he continued to work vigorously in that region. The result was the establishment of the Silurian system—under which were grouped for the first time a remarkable series of formations, each replete with distinctive organic remains older than and very different from those of the other rocks of England. These researches, together with descriptions of the coal-fields and overlying formations in south Wales and the English border counties, were embodied in The Silurian System (London, 1839), a massive quarto in two parts, admirably illustrated with map, sections, pictorial views and plates of fossils. The full import of his discoveries was not at first perceived; but as years passed on the types of existence brought to light by him from the rocks of the border counties of England and Wales were ascertained to belong to a geological period of which there are recognizable traces in almost all parts of the globe. Thus the term “Silurian,” derived from the name of the old British tribe Silures, soon passed into the vocabulary of geologists in every country.

The establishment of the Silurian system was followed by that of the Devonian system, an investigation in which, aided by the palaeontological assistance of W. Lonsdale, Sedgwick and Murchison were fellow-labourers, both in the south-west of England and in the Rhineland. Soon afterwards Murchison projected an important geological campaign in Russia with the view of extending to that part of the Continent the classification he had succeeded in elaborating for the older rocks of western Europe. He was accompanied by P. E. P. de Verneuil (1805–1873) and Count A.  F. M. L. A. von Keyserling (1815–1891), in conjunction with whom he produced a magnificent work on Russia and the Ural Mountains. The publication of this monograph in 1845 completes the first and most active half of Murchison’s scientific career. In 1846 he was knighted, and in the same year he presided over the meeting of the British Association at Southampton. During the later years of his life a large part of his time was devoted to the affairs of the Royal Geographical Society, of which he was in 1830 one of the founders, and he was president 1843–1845, 1851–1853, 1856–1859 and 1862–1871. So constant and active were his exertions on behalf of geographical exploration that to a large section of the contemporary public he was known rather as a geographer than a geologist. He particularly identified himself with the fortunes of David Livingstone in Africa, and did much to raise and keep alive the sympathy of his fellow-countrymen in the fate of that great explorer.

The chief geological investigation of the last decade of his life was devoted to the Highlands of Scotland, where he believed he had succeeded in showing that the vast masses of crystalline schists, previously supposed to be part of what used to be termed the Primitive formations, were really not older than the Silurian period, for that underneath them lay beds of limestone and quartzite containing Lower Silurian (Cambrian) fossils. Subsequent research, however, has shown that this infraposition of the fossiliferous rocks is not their original place, but has been brought about by a gigantic system of dislocations, whereby successive masses of the oldest gneisses have been torn up from below and thrust bodily over the younger formations.

In 1855 Murchison was appointed director-general of the geological survey and director of the Royal School of Mines and the Museum of Practical Geology in Jermyn Street, London, in succession to Sir Henry De la Beche, who had been the first to hold these offices. Official routine now occupied much of his time, but he found opportunity for the Highland researches just alluded to, and also for preparing successive editions of his work Siluria (1854, ed. 5, 1872), which was meant to present the main features of the original Silurian System together with a digest of subsequent discoveries, particularly of those which showed the extension of the Silurian classification into other countries. His official position gave him further opportunity for the exercise of those social functions for which he had always been distinguished, and which a considerable fortune inherited from near relatives on his mother’s side enabled him to display on a greater scale. His house in Belgrave Square was one of the great centres where science, art, literature, politics and social eminence were brought together in friendly intercourse. In 1863 he was made a K.C.B., and three years later was raised to the dignity of a baronet. The learned societies of his own country bestowed their highest rewards upon him: the Royal Society gave him the Copley medal, the Geological Society its Wollaston medal, and the Royal Society of Edinburgh its Brisbane medal. There was hardly a foreign scientific society of note which had not his name enrolled among its honorary members. The French Academy of Sciences awarded him the prix Cuvier, and elected him one of its eight foreign members in succession to Faraday.

One of the closing public acts of Murchison’s life was the founding of a chair of geology and mineralogy in the university of Edinburgh, for which he gave the sum of £6000, an annual sum of £200 being likewise provided by a vote in parliament for the endowment of the professorship. While the negotiations with the Government in regard to this subject were still in progress, Murchison was seized with a paralytic affection on 21st of November 1870. He rallied and was able to take interest in current affairs until the early autumn of the following year. After a brief attack of bronchitis he died on the 22nd of October 1871. Under his will there was established the Murchison Medal and geological fund to be awarded annually by the council of the Geological Society in London.

See the Life of Sir Roderick I. Murchison, by Sir A. Geikie (2 vols., 1875).  (A. Ge.) 


MURCIA, a maritime province of south-eastern Spain, bounded on the E. by Alicante, S.E. and S. by the Mediterranean Sea, W. by Almeria and Granada and N. by Albacete. Pop. (1900), 577,987; area, 4453 sq. m. The extent of coast is about 75 m.; from Cape Palos westwards to Villaricos Point (where Almeria begins) it is fringed by hills reaching their greatest elevation immediately east of Cartagena; northwards from Cape Palos to the Alicante boundary a low sandy tongue encloses the shallow lagoon called Mar Menor. Eastward from the Mar Menor and northward from Cartagena stretches the plain known as El Campo de Cartagena, but the surface of the rest of the province is diversified by ranges of hills, belonging to the same system as the Sierra Nevada, which connect the mountains of Almeria and Granada with those of Alicante. The general direction of these ranges is from south-west to north-east; they reach their highest point (5150 ft.) on the Sierra de Espuña, between the Mula and Sangonera valleys. They are rich in iron, copper, argentiferous lead, alum, sulphur, and saltpetre. Mineral springs occur at Mula, Archena (hot sulphur), and Alhama (hot chalybeate). The greater part of the province drains into the Mediterranean, chiefly by the Segura, which enters it in the north-west below Hellin in Albacete, and leaves it a little above Orihuela in Alicante; within the province it receives on the left the Arroyo del Jua, and on the right the Caravaca, Quipar, Mula, and Sangonera. The smaller streams of Nogalte and Albujon fall directly into the Mediterranean and the Mar Menor respectively. The climate is hot and dry, and